Calc Function

    • Calcs that help predict probability of a diseaseDiagnosis
    • Subcategory of 'Diagnosis' designed to be very sensitiveRule Out
    • Disease is diagnosed: prognosticate to guide treatmentPrognosis
    • Numerical inputs and outputsFormula
    • Med treatment and moreTreatment
    • Suggested protocolsAlgorithm





    Chief Complaint


    Organ System


    Patent Pending

    VBAC Risk Score for Successful Vaginal Delivery (Flamm Model)

    Predicts likelihood of successful vaginal birth after previous caesarean section (VBAC).
    When to Use
    Why Use

    Women in labor with history of caesarean section delivery.

    • The VBAC Risk Score for Successful Vaginal Delivery (Flamm Model) is a simple scoring system for use at labor admission to predict which patients will have a successful vaginal birth after prior caesarean section (VBAC).
    • It includes cervical assessment which can only be used after admission for labor.
    • A high VBAC Risk Score predicts success, but a low score does not necessarily predict failure; clinical judgment should be always considered.

    Determining which laboring patients are likely to have successful or unsuccessful vaginal delivery would be helpful for labor planning and shared decision making.


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    Next Steps
    Creator Insights

    Critical Actions

    A low VBAC Risk Score does not predict failure.

    Facts & Figures

    VBAC Score % of Women with Successful VBAC
    0 - 2 49
    3 60
    4 67
    5 77
    6 89
    7 93
    8 - 10 95
    Dr. Bruce Flamm

    About the Creator

    Bruce Flamm, MD, is a clinical professor of obstetrics and gynecology at the University of California, Irvine, and has practiced obstetrics and gynecology at multiple Kaiser Permanente Medical Centers. He has published dozens of papers in peer-reviewed journals and four books, including Birth After Cesarean: The Medical Facts. Dr. Flamm also serves on the editorial board of several medical journals.

    To view Dr. Bruce Flamm's publications, visit PubMed

    About the Creator
    Dr. Bruce Flamm